The long range plan of the proposed research is to study how basic processes of learning, memory, motivation, and reflexive behavior develop ontogenetically in the rat and related species. The specific areas of research are as follows: (1) Ontogeny of memory; (2) Ontogeny of learning and related processes; (3) Mechanisms for maintaining memory; (4) Ontogeny of excitation and inhibition; (5) Ontogeny of reflexive behavior; (6) Ontogeny of physiological regulatory mechanisms.